1. Field of the Invention
The present invention relates to a self light emitting display device which is adopted appropriately in electrical equipment and the like that drives and allows an indicator to emit light in a wait state in which for example a main power supply is brought to an off state.
2. Description of the Related Art
For example, many of household appliances are constructed so that ON/OFF of a main power supply switch can be controlled employing an infrared type remote control device or the like. In this case, when a video reproduction equipment or the like including for example television image receiver, display, and the like is brought to a wait mode, the main power supply switch is brought to an OFF state, and supply of a drive current to main loads (video circuit, voice circuit, and the like) is stopped. Such a wait mode corresponds to a state in which an ON command from the remote control device for the main power supply switch is waited, and minimum circuits such as a remote control signal light-receiving section, a control microprocessor, and the like are in an operation state.
In electrical equipment which can choose the wait mode in which the ON command for example from the remote control device is waited as described above and a normal operation mode in which the ON command from the remote control device is received so that the main power supply switch is in an ON state, specifically an indicator for indicating the state of the wait mode during the wait mode is disposed on the front side of the equipment. For this indicator, for example, an LED, a neon tube, or the like is employed, and there are cases where the luminous color of the indicator which is illuminated during the wait mode is determined depending on a specific nation or region.
FIG. 1 shows its example by a block diagram. In FIG. 1, reference numeral 1 designates a display panel mounted in an electrical device, and this display panel 1 is driven to be lit by a data driver 2 and a scan driver 3. As this display panel 1, a passive matrix type organic EL display panel can be employed as one example, and in this case, the voltage supplied from a main power supply B1 is boosted to a drive voltage VH by a voltage boost circuit 4 and is supplied to the data driver 2.
The drive voltage VH by the voltage boost circuit 4 is series regulated or is regulated in another way to generate a voltage VM, and this voltage VM is supplied to the scan driver 3 so that a reverse bias is given to EL elements which are brought to an non-light-emitting-state in the display panel 1, whereby so-called cross talk light emission can be prevented.
Meanwhile, reference numeral 11 designates a control microprocessor operating by a wait power supply B2, and the control microprocessor 11 is constructed such that control signals can be transmitted from this control microprocessor 11 to the data driver 2 and the scan driver 3 respectively via bus lines. A remote control signal light-receiving section and an indicator drive circuit designated by reference numerals 12 and 13 are also activated by the wait power supply B2, and an indicator 14 for example by an LED connected to the indicator drive circuit 13 is driven to emit light in the wait mode.
While the remote control signal light-receiving section 12 is in a state in which an ON command for a main power supply switch from an unillustrated remote control device is waited in a wait mode, when the command is received, a control signal is sent from the remote control signal light-receiving section 12 to the control microprocessor 11, and the control microprocessor 11 sets the main power supply switch SW to an ON state. Thus, the display panel 1 is brought to a normal operation mode in which a video signal can be displayed. At this time, the control microprocessor 11 sends a control signal to the indicator drive circuit 13 so that control by which the indicator 14 is extinguished is performed.
Disclosed in Japanese Patent Application Laid-Open No. 2003-219314 (for example, paragraph “0004”) shown below is that in this type of electrical equipment, a green color light emission LED is driven to emit light during the wait mode, and a red color light emission LED is driven to emit light during the normal operation mode.
Meanwhile, in the above-mentioned conventional electrical equipment, the indicator constituted by an LED or the like which is driven to emit light in the wait mode is constructed so as to be in an independent circuit structure together with the indicator drive circuit which drives and allows the indicator to emit light. Accordingly, in order to construct this circuit, it cannot be avoided that the manufacturing cost inevitably increases. Consumption power by the indicator constituted by an LED or the like which is driven to emit light in the wait mode and by the indicator drive circuit which is for driving the indicator cannot be ignored, and improvement of efficiency in these circuit and the like is also required.